Notes :

Please make sure that your Mac has mini DP port or Thunderbolt port.

Only one of the 3 outputs can be used at a time, you cannot use all of them simultaneously.

How to use :

You can go into “System Preferences” > “Display“. You’ll be able to see 2 display preferences dialog, one for your prime MacBook display and one for the external monitor. You can use the settings in dialogs to adjust the screen resolution, color intensity, and if you have a monitor that can be swiveled (rotated), you can tell Mac OSX to rotate the display to a certain angle for that particular display